Pitta: the colourful understorey enigma

Most readers will probably be of an age and background to have heard of The Peter Principle. But fewer, I suspect, will be au fait with the ‘pitta principle’.

The Peter Principle by Dr Laurence J Peter and Raymond Hull was written in 1969 as a satirical look at how success-based promotion eventually pushes employees to a level of incompetence. And the double irony was that for many years, it was taken very seriously by management consultants and succession planners everywhere.

The pitta principle is more ethereal and has absolutely nothing to do with the (usually) colourful tropical forest passerines this blog is about.

According to the ancient Indian Ayurveda whole body health system, if your pitta is out of whack, your symptoms could include heartburn, irritability and intolerance, excessive perfectionist tendencies and loose stools. (Put me down for all but the last one.)

All of which is another of my annoying digressions. I really want to talk about the Pittidae family and show off a few of the most engaging members to have crossed my path.

The word pitta originates from Andhra Pradesh in southern India where it is a generic term for all small birds.

Pitta were first described scientifically by Swedish botanist Carl Linnaeus in 1766 and he immediately placed them in the crow family. A decade later they were moved to the thrush family and finally got their own genus in 1816.

Once thought to number 48 species, experts have now settled on 30-32. The smallest is the blue-banded at around 15 cm and the largest is the appropriately named giant pitta at 29 cm.

Pittas tend to have colourful plumage, a trait that is unique for understorey birds. Some have bright, colourful stripes with black face masks on the head and barring on the breast. Their colours also include bright reds, blues, greens and yellows.

Tropical forest, semi-forest and scrub are their preferred haunts, so long as there is lots of cover with rich understorey and leaf litter for feeding. Earthworms, snails, termites, ants, beetles and spiders are all on the pitta’s menu.

The birds’ upperparts are generally duller, making them more difficult for predators to spot. Their most colourful plumage is usually on underparts, including rump, wings and upper tail coverts that can be covered by their wings while they are on the ground foraging.

Legs and feet

Most species also have a white wing-patch, usually seen only when they are flying. A few species have long feathers on their nape that can be raised to resemble horns.

Another unusual feature of the pitta persona is its legs and feet: they can vary considerably in colour and are thought to be used by females to judge the quality of the prospective mate.

As with most other tropical forest birds, many pitta species are threatened by human activity – particularly habitat loss. Gurney’s pitta was not seen for 34 years between 1952 and 1986 before a small population was found in southern Thailand (now down to just a few pairs).

In 2003 there was further good news with an estimated 35,000 pairs of Gurney’s found in Burma. But subsequent forest destruction is rapidly reducing those numbers.

I’ve been lucky enough to photograph a number of pitta species in Southeast Asia and Australia, and the supporting images represent a few of those wonderful finds.